Fw: blitting question

SDL Development
1

is there anyway to make a blit such that the transparency value on the
destination rectangle is the same as that on the source rectangle? I.E. if I
blit some surface (foo1) onto another (foo2), then if the top left corner of
foo1 was completely transparent, the top left corner of foo2 would be too.

-Jim Stapleton

2

I take it there is no way to do this?

-Jim Stapleton> ----- Original Message -----

From: stapleton.41@osu.edu (Steven James Stapleton)
To:
Sent: Friday, March 22, 2002 1:38 PM
Subject: [SDL] Fw: blitting question

is there anyway to make a blit such that the transparency value on the
destination rectangle is the same as that on the source rectangle? I.E. if
I
blit some surface (foo1) onto another (foo2), then if the top left corner
of
foo1 was completely transparent, the top left corner of foo2 would be too.

-Jim Stapleton

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

3

I take it there is no way to do this?

Not without writing your own custom blit function.

See ya,
-Sam Lantinga, Software Engineer, Blizzard Entertainment

4

Well, it’s not clear exactly what you mean. I mean, it seems like that if
you cleared foo2 to to the transparent color first, then blitted foo onto
foo2, then things are going to meet the requirements you set forth here. If
that’s not the answer you were looking for, or want a better answer, you
need a better question.

-Jason> ----- Original Message -----

From: stapleton.41@osu.edu (Steven James Stapleton)
To:
Sent: Monday, March 25, 2002 7:33 AM
Subject: Re: [SDL] Fw: blitting question

I take it there is no way to do this?

-Jim Stapleton

----- Original Message -----
From: “Steven James Stapleton” <stapleton.41 at osu.edu>
To:
Sent: Friday, March 22, 2002 1:38 PM
Subject: [SDL] Fw: blitting question

is there anyway to make a blit such that the transparency value on the
destination rectangle is the same as that on the source rectangle? I.E.
if
I

blit some surface (foo1) onto another (foo2), then if the top left
corner
of

foo1 was completely transparent, the top left corner of foo2 would be
too.

-Jim Stapleton

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

5

The properties of foo2 (the object being blitted to) are unknown. It could
be completely transparent, it could be solid grey, it could be blue with
pink pokadots (I hope not though…)

Anyway, Sam Lantinga answered the question.

-Jim Stapleton